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May 23, 2007

Geoengineering Reconsidered

We all know that the Earth's climate is heating up:

Now that most scientists agree human activity is causing Earth to warm, the central debate has shifted to whether climate change is progressing so rapidly that, within decades, humans may be helpless to slow or reverse the trend. . . The debate has been intensifying because Earth is warming much faster than some researchers had predicted.

Yes, it seems our planet is warming faster now than had been predicted:

Carbon dioxide emissions from fossil fuels – the principal driver of climate change – have accelerated globally at a far greater rate than expected over recent years, according to a paper published this week in the Proceedings of the National Academy of Sciences.

Scientific American says:

Global warming is occurring faster than predicted because rapid economic growth has resulted in higher than expected greenhouse gas emissions since 2000. . . Emissions from burning fossil fuels have increased about 3 percent a year since 2000, up from 1 percent a year during the 1990s, said Australia's peak scientific body, the Commonwealth Scientific and Industrial Research Organization (CSIRO).

"It means that climate change is occurring faster than has been predicted by most of the studies done through the 1990s and into the early 2000s," said CSIRO scientist Mike Raupach.

So, what can be done about it? Some scientists are proposing that geoengineering, or re-terraforming, if you will, should be considered seriously:

Much of the climate community still views the idea with deep suspicion or outright hostility. Geoengineering, many say, is a way to feed society's addiction to fossil fuels. "It's like a junkie figuring out new ways of stealing from his children," says Meinrat Andreae, an atmospheric scientist at the Max Planck Institute for Chemistry in Mainz, Germany.

But in the past year the idea has begun to re-emerge, and it now seems to be making up for lost time. In particular, the idea of blocking some of the Sun's light before it gets to the Earth — sometimes euphemistically referred to as 'radiation management' — is receiving more attention now than ever before, with new ideas about how, why and when such an approach might be taken. The most recent IPCC report, released last week, scoffs at such notions — but underlines the need for drastic approaches to stave off the effects of rising planetary temperatures. And in the context of the drastic, curiosity about geoengineering looks likely to grow.

"It's a natural question to ask," says Michael MacCracken, chief scientist for the Climate Institute in Washington DC. "If we can do something inadvertently, can we do something deliberate to counter it?"

One reason such grandiose ideas are being reevaluated now is because climate change appears to be accelerating (as noted above) and because negative impacts, some catastrophic, could start occurring sooner and more frequently than anyone anticipated.

Another reason is because science itself is accelerating, which means new technological tools for planetary engineering soon may become available. One of those tools, of course, is molecular manufacturing:

If the technological capabilities of molecular manufacturing are used effectively, disastrous climate change could be stopped in its tracks and reversed. A combination of global sensor arrays, massive computational resources, and large-area sunlight deflectors could allow climate to be understood and manipulated.

But if unstable climate, and/or unstable global economy, and/or unstable fossil fuel supplies, and/or institutional resistance to molecular manufacturing, conspire to halt its development before general-purpose exponential manufacturing is achieved, we may lose our best hope to solve the problem.

Or, if the technology is developed but is administered poorly (perhaps because of government-imposed failures of scientific accountability), then the problem is unlikely to be solved effectively.

It's not just a matter, then, of having powerful tools available. Understanding the impacts of our efforts to control a dynamic, complex system may be exceedingly difficult:

The environment could be saved or destroyed; we'll have a lot more of a choice than we do today, and a lot more information on which to base our choices. The phrase "planet-scale engineering" is not an exaggeration. Today we do planet-scale engineering in decades, except it's not really planned; we will be able to do it deliberately, in months.

Should geoengineering be required, it should be done as carefully and as reversibly as possible. More research into geoengineering is especially important in order to know what not to do.

If climate disaster hits faster and harder than anticipated, desperate people will try desperate measures, including geoengineering. We need to be able to identify the choices that won't just make things worse.

Comments

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Where is a study that says global warming is happening faster than predicted?

The conclusion that "climate change is occurring faster than has been predicted by most of the studies done through the 1990s and into the early 2000s" seems a little misleading if temperature measurements aren't increasing at a faster rate as well.

From http://www.scienceblog.com/cms/co2-emissions-increasing-faster-expected-13285.html cited above, quoting Dr Raupach, the author of the paper:

"Our results add to previous findings that carbon dioxide concentrations, global temperatures and sea level rise are all near the high end of IPCC projections."

So I think you're right that SciAm used the term "warming" without citing sources. But the more detailed writeup implies that the temperature measurements are in fact increasing faster than the average that IPCC projected.